The present invention relates in general to systems and methods for influencing sound within an enclosure and, more particularly, to a system and method that reduces the bass coloration of sound within a listening room by actively damping low-frequency boom noise, as well as other systems for actively damping noise within fluid-carrying ducts.
The experience of hearing sound in a specially designed listening environment, such as a listening room, concert hall, recording or sound studio, or other like enclosure, is affected almost as much by the dimensions of the enclosure itself as it is by the quality of the source. A properly designed listening environment enables the listener to clearly hear all of the sound or music generated by the source in the precise tone and manner in which it was intended.
A sound source generates waves that travel within the enclosure. Those waves, which travel directly from the source to the listener, are called the “direct sound” and take a few milliseconds to reach the listener. Shortly after the arrival of the direct sound, a series of semi-distinct reflections from various reflecting surfaces (e.g., walls and ceiling) will reach the listener. Moreover, other reflections of lower amplitude reach the listener after the early reflections. These reflections merge into what is called the “reverberant sound.” “Reverberant sound” is an issue in the context of fluid-carrying ducts as well, although the primary concern in fluid carrying ducts are acoustical disturbances generated from a fluid source like a pump or fan.
Consequently, there is a need for an improved system for use in reducing reverberant sound or bass coloration within an enclosure such as a listening room, and for a method for achieving such a result. The need also remains for systems that actively treat noise within fluid-carrying ducts.